Reversed-Phase Ion-Pair High-Performance Liquid Chromatographic Quantitation of Difethialone Residues in Whole-Body Rodents with Solid-Phase Extraction Cleanup.

A reversed-phase ion-pair high-performance liquid chromatographic method was developed for the determination of difethialone residues in laboratory rats (Rattus norvegicus). Difethialone was extracted from rat tissue with chloroform/acetone/formic acid. The extracts were cleaned up by a solid-phase extraction (SPE) procedure using both silica and aminopropyl SPE sorbents, concentrated, and analyzed by reversed-phase ion-pair high-performance liquid chromatography.